Vacuum closing machine



Oct. 10, 1944.

- n. )7 7'0 V/lCUl) SOURCE VACUUM CLOSING MACHINE Filed April 5, 1941 '2 Sheets-Sheet 1 j; if.

ATTOENEYS Oct. 10, 1944.

' M. E. ROBINSON ET AL VACUUM CLOSING MACHINE Filed April 5, 1941 2 Sheets-Sheet 2 ATTOEN x Patented Oct. 10, 1944 VAC'UUM CLO SING MACHINE Milton E. Robinson and Richard N. Henderson, Waukegan, Ill.. assignors to American Can Company, New York, N. Y., a corporation of New Jersey Application April 5, 1941, Serial No. 387,090 3 Claims. (c1. 226-82) This invention relates to a vacuum closing machine for friction top containers and has particular reference to closing and sealing a filled container wherein the top of such a container with a friction plug cover loosely assembled, is temporarily sealed so that the air from within the head space may be evacuated just prior to insertion of the plug cover which seals the container, the vacuumizing and sealing operations being performed during a single downward travel of suitable pressure sealing devices.

It is a usual practice to pack paints, enamels and similar products in friction top containers. This type of container is easy to close after being filled, is simple to open by an ultimate consumer and may thereafter be reclosed to preserve any remaining contents. Such containers must ordinarily be of sufficient capacity to provide space for a unit measure of the product and also to allow head space to prevent the oils and thinners contained in the paints from being forced out between the friction walls of the ring and the plug cover by any increase in the internal pressure of the closed container. Such pressure increases are likely to occur in the entrapped air of sealed cans as the result of temperature changes. Any reduction in the oil or thinner contents by leakage will vary the proportion of the ingredients of the product, as originally intended, thus adversely affecting its quality.

A larger size container for a unit quantity would leave an increased head space and might avoid paint can leakage but this would require more sheet material and consequently would involve added cost for each container. An increase in head space is also conducive to a mor rapid drying out of the surface of the paint and result in formation of a skin which cannot be used and which would be an unnecessary waste. If such a layer or skin isnot entirely removed prior to mixing the product for use and is stirred into the contents undesirable roughened particles in of which moves through a complete cycle. On the downward stroke of such a cycle the sealing head initially engages with the peripheral edge of the container, then the air from the interior of the sealing head and the head space within the container is rapidly exhausted, following which the plug cover is inserted into sealed position, the vacuum in the sealing head broken and the chuck and then the head lifted.

Another object of the invention is the provision of adjusting means in a machine of the character described wherein containers of different heights may be closed by a imple adjustment in the vertical position of the pressure chuck shaft which control the movement of the sealin head and pressure chuck.

Numerous other objects and advantages of the invention will be apparent as it is better understood from the following description, which, taken Fig. 2 is a vertical sectional detail of avacuum valve shown in Fig. -1 as viewed alon the line 22 of said figure, and showin a slide of the valve in an outward position with the valve open to the atmosphere;

Fig. 3 is a view similar to Fig. 2 showing the position of the slide when evacuating the air from the sealing head and head space of -a container;

Fig. 4 is a vertical sectional view of the valve and the slide taken substantially along thebroken line 44 in Fig. 3, showing the valve connection that leads to the vacuum source;

Fig. 5 is a front elevation of the vacuum closing machine shown in Fig. 1 and illustrating the 1 closing and vacuumizing mechanism;

Fig. 6 is an enlarged fragmentary view, partly in vertical section, of a sealing head in position against the upper double seam of a friction top container, illustrating sealing off a chamber adjacent thereto and showing the plug cover loosely resting on the container and spaced beneath a pressure closing chuck disposed in raised position prior to sealing the container; and

Fig. 7 is a view similar to Fig. 6 showing the p ure closing chuck in its lowered position and against the friction plug cover following a closing and s aling operation.

As a preferred embodiment of the invention the drawings illustrate the principal parts of a vacuum closing machine for vacuumizing, closing and sealing friction top containers. Such a container may be of the multiple friction wall variety.

The vacuum closing machine comprises a machine main frame I I having front brackets l2, l3 and I4 and a rear bracket l5. The lower front bracket 12 serves as a table or platform upon which a filled friction top container IS, with a plug cov e r.;;l'l loosely applied may be positioned for sealing. The intermediate bracket l3 and the upper bracket I 4 extend from the main frame in parallel alignment to form suitable mountings for a pressure chuck shaft I8. This shaft has reduced sections l9 and 22 at its lower end. The lowermost smallest section I9 is threadedly connected with a pressure chuck or plate 24, while the other section 22 serves as a stem upon which a movable sealing head 25 is carried.

The pressure closing chuck 24 consists of a frusto-conical shaped member having a fiat bottom surface of a diameter equal to or greater than the diameter of the friction plug cover l1. It is movable within the sealing head 25 to engage the top surface of the plug and to press it into the friction ring of a filled container.

The sealing head 25 is preferably a cast hollow bell like member having its main body part sloping outwardly and downwardly and terminating in a vertical depending wall or skirt 26. The top of the sealing head has a neck 21 and an annular ledge 28 at its base which position and support a compression spring 29. A ring 32 is assembled on the reduced section 22 of the chuck shaft against a shoulder 33 of the shaft. This supports the upper end of the spring 29. The sealing head 25 is thus normally held against the pressure chuck 24 (Fig. 1)

The depending wall or skirt 26 on the sealing head 25 has an internal annular recess 34 (Figs 1, 6 and 7) which is rectangular in cross section and which i adapted to. receive a rubber ring or sealing pad 35, also rectangular in cross section. Such a ring or pad is adapted to engage the top annular edge or double seam of the container 16; The inner surface of the wall 26 of the head is cut away and flared as at 36. This enlarges the opening and facilitates centering of the container top.

A vertical stem or connection 31 is integral with a boss or lug 38 on the sealing head 25 adjustments for can heights.

lower the pressure chuck shaft I 8 through the rack and pinion connection. This is to permit A locking screw or stud 52 is threadedly connected in the adjust- (Fig. 1). This tem is adapted to slide within a vacuum and air valve confined in a casing 39 indirectly carried on the fram of the machine. A suitable opening 42 in the stem 3'! of the sealing head (Figs. 1, 2, 3 and 4) serves as a passageway for admitting and evacuating air from the sealing head as will be hereinafter explained.

The upper front side of thgpressure chuck shaft I8 i slotted at spaced intervals as at 43 to set off a plurality of rack teeth 44 therebetween. A pinion 45 is suitably mounted in an adjustment block 46 andi arranged to have its teeth engage with the shaft teeth 44 in a rack and pinion connection (Figs. 1 and 5).

Pinion 45 is secured on a shaft 41 which is formed with a shoulder or portion of enlarged diameter 48 at one end. Apin 49 is radially disposed in this shouldered part and i adapted to be moved by hand to turn the parts carried on the shaft including the pinion 45, to raise or merit block and this may be used to lock the adjustment block to the shaft after proper adjustment is made.

A cam roller 53 is mounted on the adjustment block 45 and is operable in a cam track, groove or runway 54 of a composite face and edge cam 55. This cam is mounted on one end of a horizontal drive shaft 56 which is journaled in the machine main frame II. The face of the cam through its track 54 is adapted to reciprocate the sealing and closing mechanism in unison, while a peripheral edge or track 51 of the cam i designed to operate the vacuumizing mechanism.

The edge or track 51 provides the cam surface for a cam roller 58 which is carried on one end of a cam lever 59. The lever is pivotally mounted upon a lug 62 which may be an integral part of the frame H. The lower end of the lever has an elongated slot 63 in which a valve slide lug 64 is connected. A stud or pin 65 forms a pivotal connection for the lever and the slide lug. Such a lug extends from one end of a tubular slide valve 66 constituting a movable part within the vacuum valve casing 39.

A cam lever tension spring 61 (Fig. 5) has one end connected to a lug 68 on the lever and its opposite end connected to a lug 69 extended from the frame II. This arrangement maintains the cam roller 58 in operative engagement with and against the cam edge surface or track 51.

The air and vacuum valve casing 39 is fixed to the lower face of the frame bracket l3 so that the stem 31 is free to move vertically in a valve chamber 12 (Figs. 1, 2, 3 and 4) as the sealing mechanism is raised and lowered by the pressure chuck shaft l8. A horizontal cylindrical valve chamber 13 is formed in the valve casing 39 and the slide valve 66 is cam actuated and moved therein by the cam and lever connection hereinabove described. Thi slide valve 66 opens and closes connection with a vacuum source which is made effective at the valve by mean of a pipe 14 communicating with such source (not shown) (Figs. 1 and 4).

The vertical and horizontal valve chambers 12, 13 in the valve casing 39 (Figs. 2, 3 and 4) are joined by a communicating port or channel 15. The slide valve 66 also has a central chamber 18, a side port 11 and a lower or bottom port 18. The port 18 in one position of the slide valve communicates with the chamber 12 by way of the port or channel 15.

Each port is adapted to be closed off at times or the side port may register with a side valve vacuum port 19 cut in the casing 39, or the bottom valve port 18 with the port channel 15. When the slide valve 66 registers the ports 1'! and 19 air is evacuated from the system, this including the sealing head and the container head space. This constitutes a vacuumizing step (Figs. 3 and '4). The outer section of the side valve vacuum port 19 is threaded for the pipe connection 14 (Figs. 1 and 4') in turn leading as described to a proper source of vacuum.

When the valve slide 66 is moved to the position illustrated in Fig. 2, which takes place following a sealing operation, the vacuum source is sealed off and the port channel 15 is uncovered. A vent opening 82 disposed in an end wall 83 of e valve ide chamber in the casing 39, main- .A single revolution :clutch 458 :also is mounted on the :drive :shaft '56 ,and is .arranged .to intermittently operate certain .parts of the machine. Such a clutch may be:of the :type fully illustrated in the ,J. :G. Hodgson Patent 681,023, issued August 20,:l-901, .on a Power Press. Figure 1 of the drawings lbriefly illustrates the operating and :release mechanism associated (with such .a clutch, part of which is mounted on the frame :H of the machine while the remainder is connectedwith the :gear.

-A lever .39 .is pivotally mounted on the main frame H and has an end 92 connected to the clutch operating :parts. The oppositeend of the lever terminates in a rounded part 93 which is adapted to slide on .an inclined tail part 94 of a contact lever 95. This contact lever is pivotal-1y mounted on the machine main frame II as *on astud 96.

.A lower end. 91 of the lever 95 is threaded to receive 1'3, :threaded stud or bolt 98, the head of which is :rounded off as at '99. This head serves as a contact for the filled friction top cans which press against the head when the can is placed upon the bracket 12. By pushing in the lever head, the vacuumizing, closing and sealing operations begin. Adjustment as to position of the head of the threaded stud compensates for variation in diameters of cans vacuumized and sealed by the machine.

When the container I6 is to be closed after filling, the friction plug cover I! is loosely positioned over a friction ring I02 (Fig. 6) of the can so that a plug section I03 on the cover rests lightly in a U-shaped channel I04 of the ring. The container I6 is then placed upon the bracket l2 of the machine and is pushed rearwardly to a position directly beneath and axially of the sealing head 25. Such movement shifts the contact lever 95 to the left (Fig. 1) and thus rocks the lever 89 which immediately operates the clutch mechanism in the manner described in the Hodgson Patent 681,023 aforesaid.

The can controlled actuation and operation of the clutch permits a single rotation only of the shaft 56 which in turn effects one rotation of the composite face and edge cam 55. This cam as previously described operates both the pressure chuck shaft l8 and the valve slide 66. The motion imparted to the shaft I8 lowers the closing and sealing mechanism and during this downward stroke, the filled container is temporarily sealed off from atmosphere, is vacuumized and finally is closed.

The pressure chuck shaft l8 during its single downward stroke carries with it both the pressure chuck 24 and the sealing head 25 so that the sealing head first engages upon the peripheral edge of the container IE to seal off the container (Fig. 6) from the atmosphere. The valve slide 66 is then moved from the position illustrated in Fig. 2 to that shown in Figs. 3 and 4 whereupon the system is directly connected with the vacuum source and the air is evacuated from the sealing head ror 'sealedoff chamber and from the .ihead spacepf the container. This actionzprecedesen- 'gagement of the pressure chuck and the plug cover 1'1.

Thespring 29.carried.by:the sealing mechanism being yieldable, permits further motion of the pressure chuck 24 after the sealing head 25 has come to rest in its position on the container 1.6 (-Fig. 61).. The pressure chuck thus moving down against the resistance of thespring engages and inserts 'the plug 'cover I! into the can. At the end :of the :down stroke (Fig. 7') the valve slide is againmoved :out to the position illustrated in Fig. :2and this seals :off the vacuum by uncoveringtthe portchannel' 'l5 in the valve-and'opening ithe inside .of :the sealing head to atmosphere. This facilitates the separationof the sealing head from the sealed container 'when the rising chuck, afterzpassing through the position of Fig.6, raises the .sealing .head .as :both members return to initiakstarting position. This return is made upon the upward movement of the pressure chuck shaft on the .second half of the single working cycle. The sealed .container IB may then be removed from the bracket [-2, replaced by another filled container-and the operation repeated,

It .is thought that the invention and many of its attendantadvantages will'be understood from the :foregoing description, and it will be apparent that various changes may be made in the form, construction :and arrangement of the parts without departing from the spirit and scope of the inventionor sacrificing all of its material advantages, the form hereinbefore described being merely a :preferred embodiment thereof.

We claim:

1. A machine for vacuumizing and closing filled friction top containers, comprising a support for a. filled container, a vertically movable shaft, a pressure chuck secured to said shaft, a sealing head carried by said shaft and movable with the shaft and chuck during part of a downward stroke of the shaft, a source of vacuum communicably connected to said sealing head and a valve hous ing having an axially reciprocable valve therein disposed between said head and vacuum source, means for moving said valve for controlling communication with said vacuum source, and means operatively connected to said valve moving means and to said shaft for vertically moving the shaft relative to said container support to move said shaft downwardly to engage said sealing head with the top of a supported container having a loosely applied cover for sealing off a closed chamber including the container head space beneath said loosely applied cover and to thereafter actuate said valve moving means to establish communication between said vacuum source a and said chamber to vacuumize the latter, said shaft being operable on further downward movement to engage said chuck with the loosely applied cover to insert the latter into sealing engagement with the evacuated container and thereafter to actuate said valve moving means to shut off communication with said vacuum source while venting said chamber to atmosphere.

2. A machine for vacuumizing and closing filled friction top containers, comprising a support for a filled container, a vertically disposed and movable shaft, a pressure chuck secured to said shaft, a sealing head carried by said shaft and movable with the shaft and chuck during part of a downward stroke of the shaft, a source of vacuum communicably connected to said sealing head and a valve housing having an axially reciprocable sliding valve therein disposed between said head and vacuum source, means for moving said valve, a rotatable cam operatively connected to said valve moving means and to said shaft for vertically moving the shaft relative to said container support to move said shaft downwardly to engage said sealing head'with the top of a supported container having a loosely applied cover for sealing off a closed chamber including the container head space beneath said loosely applied cover and to thereafter actuate said valve moving means to establish communication between said vacuum source and said chamber to vacuumize the latter, further downward movement of the shaft engaging said chuck with the loosely applied cover to insert the same into sealing engagement with the evacuated container and thereafter to actuate said valve moving means in the opposite direction to shut 01f communication with said vacuum source while venting said chamber to atmosphere, and means for controlling the extent of downward movement of said shaft to adapt the machine for closing friction top containers of varying heights.

3. A machine for vacuumizing and closing filled a valve housing having an axially reciprocable' sliding valve therein disposed between said head and vacuum source, a pivoted lever connected to said valve for moving the same, a rotary cam having its peripheral edge engaging said lever and having a cam track operatively connected through a cam roller and rack and pinion connection to said shaft for vertically moving the shaft relative to said container support to move said shaft downwardly to engage said sealing head with the top of a supported container having a loosely applied cover for sealing off a closed chamber including the container head space beneath said loosely applied cover and to thereafter actuate said pivoted lever to establish communication through said valve between said vacuum source and said chamber to vacuumize the latter, further downward movement of the shaft serving to engage said chuck with the loosely applied cover to insert the same into sealing engagement with the evacuated container and to thereafter actuate said pivoted lever in the opposite direction to shut off communication through said valve with said vacuum source while venting said chamber to atmosphere, a clutch controlled power shaft for rotating said cam, lever mechanism connected to said clutch and engageable by a container placed on said support for actuating the clutch to drive said power shaft and said cam for a single revolution only to actuate said sealing head, pressure chuck and valve in timed relation for the purposes de-' scribed during a single downward movement of said vertically movable shaft, and a rack and pinion connection for controlling the extent of downward movement of said shaft to adapt the machine for closing friction top containers of varying heights.

MILTON E. ROBINSON. RICHARD N. HENDERSON. 

